The present invention relates to a cooling element for an object, in particular for a high-voltage battery. Furthermore, the invention relates to a high-voltage battery which includes a cooling element of this type.
Vehicles, in particular electric vehicles and hybrid vehicles, are known in the prior art. In order to ensure the range, service life and power that can be demanded by electric vehicles or hybrid vehicles, a predefined temperature management of the high-voltage batteries of the vehicles is required. It is crucial for this purpose that a temperature spread between individual cells of the high-voltage batteries is kept as low as possible. To this end, use is made of refrigerants which safely and reliably cool the high-voltage batteries, in particular by way of a cooling circuit of the vehicle.
If a plurality of high-voltage batteries are present in a vehicle, care should be taken in particular to ensure that all of said high-voltage batteries undergo uniform cooling. However, this cannot be realized with cooling elements from the prior art.
It is therefore the object of the invention to provide a cooling element for an object, which cooling element ensures safe and reliable cooling of the object while being simple and cost-effective to produce and install.
This and other objects are achieved by a cooling element according to embodiments of the invention. A cooling element is provided which can be used for an object, in particular for a high-voltage battery. The cooling element comprises a refrigerant inlet and at least one distributor. A refrigerant can be supplied to the cooling element at the refrigerant inlet, wherein the cooling element is designed to transmit heat from the object to the refrigerant. The refrigerant inlet is, in particular, part of a main line of the cooling element, wherein the main line is connected to the distributor. The distributor serves for dividing the refrigerant between a multiplicity of parallel lines. The refrigerant entering the main line through the refrigerant inlet is therefore divided into a multiplicity of parallel lines, wherein the parallel lines advantageously serve for cooling the object. A plurality of objects are preferably present, wherein at least one cooling line cools at least one object.
According to the invention, the refrigerant in the cooling element is present as a two-phase mixture. The distributor is designed in turn, according to the invention, to distribute the refrigerant uniformly between the lines. Since a uniformly distributed temperature always has to be present, in particular in a high-voltage battery, the cooling element according to the invention is advantageously usable. Uniform cooling of the object is ensured by the uniform division of the refrigerant into the individual parallel lines. Therefore, a high-voltage battery, in particular, is optimally cooled, and therefore the high-voltage battery permits a long service life and optimum energy storage and energy output.
The distributor is preferably designed such that the distributor divides the refrigerant between the parallel lines in such a manner that the same mixing ratio of the two-phase mixture is present in each parallel line. The same mixing ratio is particularly preferably present in each parallel line and in the main line. In the main line, the refrigerant is present in particular as a mixture of liquid and gaseous phase constituents. In order to ensure uniform cooling of the object, it is provided in particular that each parallel line has the same mixing ratio as in the main line. This can be achieved in an advantageous manner by the cooling element according to the invention with the preferred configuration of the distributor. The advantageously configured distributor therefore permits safe and uniform cooling of the object.
The cooling element is advantageously designed in such a manner that a predefined region of the main line directly upstream of the distributor includes exclusively rectilinear sections. The predefined region of the main line therefore has a homogeneous mixing ratio of the refrigerant. The refrigerant with the homogeneous mixture is therefore divided in the distributor such that each parallel line also has the homogeneous mixture. Alternatively, there is at least one curved section in the predefined region of the main line. It is additionally preferably provided here that the curved section has a source of interference. The source of interference is, in particular, an edge and is advantageously arranged in a radially outer inner wall of the main line. Homogenization of the refrigerant is thereby achieved. In particular, in the curved section, a liquid phase constituent is separated from a gaseous phase constituent since the latter is pressed against the radially outer inner wall of the main line by a centrifugal force which is present. By means of the source of interference, the refrigerant is advantageously homogenized by the liquid phase constituent being separated from the inner wall.
In addition, the cooling element is preferably designed in such a manner that all of the parallel lines are arranged vertically in the same plane. Alternatively, the parallel lines are arranged at least substantially vertically in a plane. As a further alternative, the parallel lines are arranged at different height levels, wherein the distributor or a section of the main line directly upstream of the distributor includes a source of interference. The source of interference is, in particular, an edge on an inner wall of the main line. Homogenization of the refrigerant is achieved by the source of interference. This avoids a separation of the two-phase mixture, which separation may take place by the distribution of the refrigerant between parallel lines which are arranged horizontally in different planes. Since liquid phase constituents are accumulated on horizontally lower planes due to gravity, there is the risk that parallel lines positioned high up vertically will obtain only gaseous phase constituents and parallel lines positioned down low vertically will obtain only liquid phase constituents. The preferred provision of a source of interference homogenizes the refrigerant, and therefore each parallel line obtains the same phase mixture even in the event of different height levels.
The cooling element is advantageously designed in such a manner that a pressure loss within the parallel lines is identical or at least substantially identical. By way of the identical pressure loss, a coolant flow within the parallel lines is also identical or at least virtually identical. A cooling line of the individual parallel lines is therefore identical or at least substantially identical.
In addition, a predefined distance is advantageously maintained between an expansion valve and the distributor. Since an expansion valve has effects on the phase composition of the refrigerant, the predefined distance is maintained. Homogenization of the refrigerant is achieved within the predefined distance, and therefore the distributor distributes the homogeneous refrigerant to the parallel lines.
A nozzle is preferably present in the main line directly upstream of the distributor. The nozzle homogenizes the refrigerant, and therefore the distributor obtains a homogeneous refrigerant and thus distributes the homogeneous refrigerant to the parallel lines. The use of the nozzle is, in particular, advantageous if the abovementioned predefined distance between the expansion valve and the distributor is not maintained.
The cooling element advantageously has a reduction in at least one of the parallel lines. The reduction makes it possible, in particular, to equalize pressure losses within the parallel lines. A reduction is thus advantageously provided in a parallel line which otherwise, compared with the other parallel lines, would have a smaller pressure loss and therefore an increased cooling power. The reduction according to the invention therefore ensures uniform cooling of the object.
The cooling element preferably has a symmetrical distributor. By way of the symmetrical distribution, the same mixing ratio of the refrigerant is transmitted to the parallel lines. An identical distribution of the refrigerant to the parallel lines can therefore be achieved.
Finally, it is provided according to the invention that the two-phase mixture has a liquid and a gaseous phase. This is advantageous in the configuration of refrigerant circulation processes.
The invention furthermore relates to a high-voltage battery which includes the previously described cooling element. The high-voltage battery advantageously has a plurality of battery modules, wherein each battery module is assigned at least one parallel line. The high-voltage battery can be cooled in particular uniformly by the cooling element, and therefore temperature spreads between the battery modules of the high-voltage battery are very substantially avoided. A service life and/or an energy storage capacity and/or an energy output capacity of the high-voltage battery are/is therefore advantageously optimized.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.